Engines have used electronic engine controllers for many years to perform various functions related to the engine. For example, they may be used to reduce “knocking” in engines. “Knocking” is uncontrolled fuel combustion detrimental to emissions, fuel economy, and engine longevity. In addition, they may also be used to control valves in an engine for fuel injection control. Thus, electronic engine controllers are an important component of engine-driven machines.
Engines, including diesel engines, gasoline engines, natural gas engines, and other engines in the art, may exhaust air pollutants. The air pollutants may be composed of both gaseous materials and solid particulate matter. Particulate matter may include carbon particles called soot. In addition, particulate matter may contain ash, a material that can be used in engine oils to reduce the acidity of the oil.
The particulate matter generated by an engine may be filtered from an exhaust stream. Various technologies may be used to filter particulate matter from an exhaust stream. One of these technologies includes the use of an exhaust element, such as a particulate filter. Particulate filters trap particles in the exhaust stream, so the exhaust stream is cleaner when it enters the air.
Particulate matter trapped by the filter can accumulate in the filter and reduce the operating efficiency of the engine. As particulate matter in the filter accumulates, the back pressure to the engine can increase. Therefore, the engine may consume more fuel to produce the same amount of power as compared to an engine with a filter free of particulates.
These and other problems may be avoided by periodic cleaning of the filter. Various methods of cleaning filters exist in the art. One method includes heating the particulate matter trapped in the filter to a temperature at which it combusts or vaporizes. This type of filter cleaning may be referred to as regeneration. Various regeneration techniques may be used to regenerate a particulate filter. One technique involves the use of a diesel burner that may be used to heat the particulate matter trapped in the filter.
The regeneration process may be controlled by an aftertreatment controller to help control and improve the efficiency of the regeneration process. For example, the controller may improve efficiency by controlling the amount of fuel used for regeneration. To control the amount of fuel used for regeneration, the controller may be configured to determine the amount of particulate matter that needs to be heated and only cause the usage of an amount of fuel that is actually required to heat the particulate matter.
It may be helpful to connect the engine controller to the aftertreatment controller. This interconnection may enable the engine controller to share information with the aftertreatment controller. This information may assist the aftertreatment controller to control the regeneration process efficiently. In addition, this interconnection may also enable the aftertreatment controller to share information with the engine controller. This information may assist a user to troubleshoot problems with the aftertreatment controller more efficiently.
Various systems have been proposed where information is exchanged between an engine control unit and an aftertreatment control unit. One such system is disclosed in U.S. Patent Application Publication No. US 2004/0211159 A1 to Hamahata et al (“the '159 publication”), which published on Oct. 28, 2004. This publication describes an apparatus where a filter control unit sends a signal to the engine control unit after determining that the filter control unit needs to regenerate the filter. In response to this signal, the engine control unit modifies engine operation to elevate the exhaust gas temperature for regeneration of the filter. The engine control unit also sends a signal to the filter control unit that contains a temperature differential value. The filter control unit determines the time to stop regeneration based on this value. Thus, the exchange of these signals helps the regeneration of the filter.
While the apparatus of the '159 publication may be used to control the regeneration of a filter, the apparatus has several shortcomings. The apparatus does not use any data link protocols for communication between the filter control unit and the engine control unit. Therefore, as known in the art, a separate connection between the filter control unit and the engine control unit is required for each signal sent between the two units. Therefore, because the apparatus of the '159 publication does not use a data link protocol for the communication between the filter control unit and the engine control unit, the apparatus would require an additional connection between the filter control unit and the engine control unit for each additional signal that would need to be exchanged between the two units. As the number of signals that need to be exchanged between the filter control unit and engine control unit increases, the number of connections between the two units would have to be increased by the same number. However, it may not be practical to increase the number of wires between the filter control unit and engine control unit because of space and cost considerations.
This limitation would limit the number of signals that may be exchanged between the filter control unit and the engine control unit in the '159 apparatus. As shown in the '159 publication, the availability of only two connections between the engine control unit and the filter control unit may only permit the passage of the two signals (temperature differential value and regeneration signal) between them. These signals may not provide the filter control unit enough information to control the regeneration process effectively and efficiently. For example, the filter control unit has no information about the operating conditions of the engine. Lack of this information may cause the filter unit to use more or less fuel for regeneration than necessary, thus affecting fuel efficiency. The filter control unit may also not be able to send a signal indicating its operational status to the engine control unit. This lack of information being sent from the filter control unit to the engine control unit may reduce the diagnostic measures available for troubleshooting any regeneration related problems because there may be no indication of a malfunction in the regeneration apparatus.
The present disclosure is directed to overcoming one or more of the problems associated with the prior art regeneration method.